Controller for steering device

Abstract

A controller for a steering device includes an electronic control unit configured to control the steering device. The electronic control unit is configured to acquire an action force and to calculate a basic reaction force based on the acquired action force. The action force includes at least two of axial forces of a plurality of types and a tire force. The axial forces of a plurality of types are applied to a turning shaft that is connected to turning wheels. The tire force is applied to the turning wheels. The electronic control unit is configured to, when one predetermined force of the acquired action force is abnormal, calculate the basic reaction force such that a contribution proportion of the predetermined force to the basic reaction force is lower than a contribution proportion when the predetermined force is not abnormal.

What is claimed is: 
     
       1. A controller for a steering device in a vehicle, the controller comprising:
 an electronic control unit configured to control the steering device, 
 the electronic control unit being configured to:
 acquire an action force based on a plurality of state quantities in the vehicle and to calculate a basic reaction force based on the action force, the action force including at least two of axial forces of a plurality of types and a tire force, the axial forces of the plurality of types being applied to a turning shaft that is connected to turning wheels in the vehicle, and the tire force being applied to the turning wheels, wherein the plurality of state quantities being used to acquire the action force includes a current value of a turning-side motor of the vehicle, a target steering angle, and a vehicle speed, 
 determine, for each one of the plurality of state quantities including the current value of the turning-side motor of the vehicle, the target steering angle, and the vehicle speed, whether or not a respective state quantity is abnormal indicating that the respective state quantity has an impossible value or a change from a previous value that is greater than a preset threshold, 
 when one of the plurality of state quantities is determined to be abnormal,
 determine that a predetermined force of the action force which is acquired based on the one of the plurality of state quantities is abnormal, and 
 calculate the basic reaction force using a contribution proportion of the predetermined force to the basic reaction force that is lower than a preset contribution proportion of the predetermined force to the basic reaction force, the preset contribution proportion being a value that is stored and is used to calculate the basic reaction force when the predetermined force is not abnormal, 
 
 determine a steering reaction force based on the calculated basic reaction force, and 
 apply the steering reaction force, which is a force resisting steering of the vehicle, to the steering device of the vehicle. 
 
 
     
     
       2. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device having a structure in which a steering unit and a turning unit that turns the turning wheels in accordance with steering which is input to the steering unit are mechanically separated from each other,
 wherein the electronic control unit is configured to control operation of a steering-side motor that provides the steering reaction force and the steering reaction force is a force resisting the steering which is input to the steering unit, 
 wherein the electronic control unit is configured to calculate the target steering angle using a reaction component based on the basic reaction force and the target steering angle is a target value of a steering angle of a steering wheel that is connected to the steering unit, and 
 wherein the electronic control unit is configured to calculate a target reaction torque based on execution of angle feedback control, the angle feedback control causes the steering angle to follow the target steering angle, and the target reaction torque is a target value of the steering reaction force. 
 
     
     
       3. The controller for the steering device according to  claim 2 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       4. The controller for the steering device according to  claim 2 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       5. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device having a structure in which a steering unit and a turning unit that turns the turning wheels in accordance with steering which is input to the steering unit are mechanically separated from each other,
 wherein the electronic control unit is configured to control operation of a steering-side motor that provides the steering reaction force and the steering reaction force is a force resisting the steering which is input to the steering unit, and 
 wherein the electronic control unit is configured to calculate a target reaction torque based on a steering torque which is applied to the steering unit and a reaction component based on the basic reaction force and the target reaction torque is a target value of the steering reaction force. 
 
     
     
       6. The controller for the steering device according to  claim 5 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       7. The controller for the steering device according to  claim 5 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       8. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device having a structure in which a steering unit and a turning unit that turns the turning wheels in accordance with steering which is input to the steering unit are mechanically separated from each other,
 wherein the electronic control unit is configured to control operation of a steering-side motor that provides the steering reaction force and the steering reaction force is a force resisting the steering which is input to the steering unit, and 
 wherein the electronic control unit is configured to calculate a target reaction torque using a reaction component based on the basic reaction force and the target reaction torque is a target value of the steering reaction force. 
 
     
     
       9. The controller for the steering device according to  claim 8 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       10. The controller for the steering device according to  claim 8 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       11. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device that applies an assist force for assisting a steering operation to a steering mechanism using an assist mechanism with a motor as a drive source,
 wherein the electronic control unit is configured to calculate a first assist component based on a steering torque, 
 wherein the electronic control unit is configured to calculate a target rotation angle using a reaction component based on the basic reaction force and the target rotation angle is a target of a rotation angle of a rotation shaft which is able to convert a turning angle of the turning wheels, 
 wherein the electronic control unit is configured to calculate a second assist component through execution of angle feedback control based on the rotation angle and the target rotation angle, and 
 wherein the electronic control unit is configured to control operation of the motor such that an assist force according to an assist command value based on the first assist component and the second assist component is generated. 
 
     
     
       12. The controller for the steering device according to  claim 11 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       13. The controller for the steering device according to  claim 11 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       14. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device that applies an assist force for assisting a steering operation to a steering mechanism using an assist mechanism with a motor as a drive source,
 wherein the electronic control unit is configured to calculate a torque command value and the torque command value is a target value of a steering torque which is to be input to the steering mechanism, 
 wherein the electronic control unit is configured to calculate a first assist component through execution of torque feedback control based on the steering torque and the torque command value, 
 wherein the electronic control unit is configured to calculate a target rotation angle using a reaction component based on the basic reaction force and the first assist component and the target rotation angle is a target of a rotation angle of a rotation shaft which is able to convert a turning angle of the turning wheels, 
 wherein the electronic control unit is configured to calculate a second assist component through execution of angle feedback control based on the rotation angle and the target rotation angle, and 
 wherein the electronic control unit is configured to control operation of the motor such that the assist force according to an assist command value based on the second assist component is generated. 
 
     
     
       15. The controller for the steering device according to  claim 14 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       16. The controller for the steering device according to  claim 14 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       17. The controller for the steering device according to  claim 1 , wherein the electronic control unit is configured to control the steering device that applies an assist force for assisting a steering operation to a steering mechanism using an assist mechanism with a motor as a drive source,
 wherein the electronic control unit is configured to calculate a torque command value using a reaction component based on the basic reaction force and the torque command value is a target value of a steering torque which is to be input to the steering mechanism, 
 wherein the electronic control unit is configured to calculate an assist command value through execution of torque feedback control based on the steering torque and the torque command value, and 
 wherein the electronic control unit is configured to control operation of the motor such that the assist force according to the assist command value is generated. 
 
     
     
       18. The controller for the steering device according to  claim 17 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that the contribution proportion of the predetermined force to the basic reaction force is zero. 
     
     
       19. The controller for the steering device according to  claim 17 , wherein the electronic control unit is configured to, when the predetermined force is abnormal, calculate the basic reaction force such that a contribution proportion of a force other than the predetermined force to the basic reaction force is higher than a contribution proportion of the force other than the predetermined force to the basic reaction force when the predetermined force is not abnormal. 
     
     
       20. The controller for the steering device according to  claim 1 , wherein
 the at least two of axial forces of the plurality of types are a current axial force and an angle axial force, 
 after determining abnormality of each of the plurality of state quantities including the current value of the turning-side motor of the vehicle, the target steering angle, and the vehicle speed;
 the current value of the turning-side motor of the vehicle is input to calculation of the current axial force, and 
 the target steering angle and the vehicle speed are input to calculation of the angle axial force; 
 
 the calculated current axial force, the calculated angle axial force, the tire force, and an output signal from the determination of the abnormality of each of the plurality of state quantities are input to calculation of the basic reaction force.